Broaching machine



Aug. 4, 1953 Filed July 9, 1948 A. A. WEISBERGER ETAL BROACHING MACHINE 2 Sheet's-Sheet l Aug, 4, 1953 Filed July 9, 1948 A. A. wElsBERGl-:R ErAL BROACHING MACHINE 2 Sheets-Sheet 2 Patented Aug. 4, 1953 Arthur A. Weisberger and Robert J. Helton, Hammond, Ind., assignors to American Steel Foundries, Chicago, Ill., a corporation lof New Jersey Application July 9, 194s, serial No. 37,918

11 claims.

This invention relates to machinev tools and more particularly to machines,` such as broaches, for forming holes in associated work pieces.

A general object of the invention is to devise a novel broaching machine particularly adapted to broach a hole in an associated work piece and thenlpressing a bushing vin the hole Without distorting thebushing.

Infpriorart'machines of the above-described type,'the bushing has been mounted on the large end ofthe broach to accommodate pressing of the bushing into the hole after thebroach has passed therethrough. However, it has been found that due to imperceptible misalignment of `the broach, the opening is frequently formed on al bias resulting in distortion of the bushing as it is pressed into'the hole. This condition has resulted in the expensive and troublesome practice A further obj-ect of ing machine of the above type, comprising means for effecting a relatively slow initial return movement of the broach by the retriever device whereby the operator may apply a bushingr to vthe large end of the broach before it is rapidly re-engaged kwith its actuating power device.

The foregoing and other objects. and advantages of the invention will become apparent from a consideration of the following specification and the accompanying drawings, wherein:

Figure 1 is a diagram of the hydraulic system and associated electrical actuating circuits for a broaching machine embodying the invention, the

b broaching machine being diagrammatically illusof grinding the bushings after assembly thereof.

Accordingly, a primary object of the present invention is to positively center the lbroach with respect to the work piece at al1 times during broaching of the hole thereby-insuring aperfect fit of the bushing and consequently'preventing distortion thereof.

Another significant disadvantage' of prior art broaching machines of the above vtype has been the necessity for the operator to retrieve the broach Vat the end of each operation. This practice requires manual handling of the broach resulting in loss of time and in operator fatigue.

Accordingly, another object of the invention is to devise a broaching machine of the abovedescribed type wherein manual handling of the broach is eliminated by the provision of means for retrieving the broach and re-engaging it with its actuating power device at the end of each operation.

A further object of the invention is to provide a dual purpose device for centering and retrieving the broach as above described. l

trated with portions broken away in vertical section to clarify the operation of the machine;

Figure 2 is a sectional View through the broach centering device taken on the line 2 2 of Figure 1; and f Figure 3 is an enlarged fragmentary view principally in central vertical section of the broach actuating chuck and the work table, with the chuck illustrated on the return or pullback stroke thereof.

Describing the invention in detail and referring r'first to Figure 1, the novel broaching machine comprises a broach actuating power device, generally designated 2, which, in the illustrated embodiment of the invention, is in the form of an hydraulic motor comprising an hydraulic cylinder 4 and an hydraulic ram 6 reciprocal therein, the ram having a head 8 defining an advance chamber I0 and areturn or pullback chamber I2 Within the cylinder 4. The machine isv illustrated in the form of a so-called vertical broach- Stillanother object of the invention is ito pro- L vide a novel nuid control circuit for thev broach retrieving device to advance the latter and thereby engage the broach with its actuating power device, said system also comprising means for permitting the retrieving device to be urged toward retracted position under the pressure of the broach. Y

Still another object of the invention is to devise a novel broaching machine, such as above described, wherein the. operating cycle is automatic, thereby relieving the operator of the necessity for. actuating the machine .except to initiate ,eah Cycle thereof.-

l ing machine, and the lower end of the ram 6 is provided with a broach engaging chuck mechanism, generally designated I4, comprising a pres-` sure head I6 secured to the ram as by threaded engagement therewith at I8. The head I6 clamps a spring plate 20 against the lower end of the ram and is provided with a socket 22 adapted to receive a complementary nose or lug 24 on the upper or large end of a broach 26, the nose 24 comprising a recess 28 adapted to cooperate with an associated latch mechanism 30, hereinafter described in detail. The latch mechanism is resiliently urged to operating position by a collar 32 actuated by a spring 34 bearing against the under side of the plate 2D.

The large end of the broach is provided with a shoulder 36 aiording a seat for a bushing 38, and the small, lower end of the broach is prothe invention is to provide an automatic control system for a broachvided with a nose or lug 40 adapted for reception within a complementary socket 42 of an associated centering chuck 44 disposed in predetermined alignment with the chuck I4 for a purpose hereinafter described in detail. The chuck 44 operates within an opening 46 of a work support member 48 carried by a table 50. The member 48 is adapted to support an associated work piece, indicated in phantom lines at 52.` y

The chuck 44 is connected to a piston rod 54 operated by a piston 56 reciprocal within a pneumatic cylinder 58 and dening advance and return chambers 66 and 62 therein. The advance-.1. 5,-...

chamber 60 is connected to a flexible advance line 64, and the return chamber 62 is :connected-.to a 1. exible return line 66, said lines beingconnectemi. to a conventional operating valve68-which-isJ operated, as hereinafter described lindetail, ,-by, f

a pair of solenoids 10 and 12 whereby, in the ad- Vance position of the valve 68, pneumatic pressure delivered thereto by a supply line 14 is clelivered to the advance line 64 and pneumatic 1 fiuidis exhausted from the returnline {i6-,through In the return, orqpullback; position of the valve 66, pneumatic pressure fluid is delivered to the return line 66 and isexhausted from the advance line 64 through another .exf-

an exhaust line 15.

haustv'line 15.

The lower end ofthe cylinder 50 lisypivotally` connected as at 16 to a lever 16 having afloating pivotal. fulcrum :as at 80 to a link 6,2 .pivoted-at@ 84 to va bracket 86 carried by the frameof-,the

machine, fragmentarily indicated'aty 81.3 YThe lever. 18 is pivotally lconnected intermediateitsj ends as at 68 to a piston rod 96which1isopera: l i tively 4connected to a piston 92 reciprocal` with- .V in :an-hydraulic retriever cylinder 94 and derin-l ing advance .and return -chambers 96, and .964 therein. The upper end of the cylind,1':94 iS.' from a` .braolfzetH `The-pistonl 92,... is operated to advance and retract the pneumaticvk pivotally. supported as at |02 of-the machineI frame 81.

fluid pressure device 56, 8 which operates ./,the

centering-rand retrieving chuck 44 fora purpose hereinafter described.

The `pistonl 92 is operated by hydraulic-.. 1hiid--.l admitted to the advance chamber 96 by an ad- Vance line v|64 and to the return chamber-,96

by a return or pullback line |06. The linesl |04 and |06 are connected to an operating-va1ve. generally designated |66. The valve |08 is' similar to the valve -68 and comprises a casing. ||0 f fr. having an internal cylindrical bore I2 .receiving a stem H4 having a plurality of lands or. spools I|6 slidably fitted within the bore in substan--z tially- :fluid-tight engagement therewith. The

stem H4 comprises a longitudinal internal pas- -f sage IIS communicating with ports |20 through..

the lands I I6 in the neutral position of the valve stem.||4. Thus in the neutral position of the stem,. pressure fluid is delivered.l from a pressure... line |22 to the bore I|2 and thence to the passage I i8 and ports |26 to an exhaust or discharge. line |24 connected to a reservoir |26 of low pres-` sure hydraulic iiuid. The line |22 is supplied with pressure fluid by a pump |28 having its suc- .f tion side connected to the tank |26 and having'y its discharge side connected to the line |22 which is provided with a conventional relief valve |30 `adapted to open the line |22 to communication with the tank |26 through a relief line |32 whenever the pressure in the line |22 exceeds apredetermined operating value.

lIhe stem I4 of valve |08 is shifted to advance position, as hereinafter described in detail, by' a:

4 solenoid |36, whereupon pressure iiuid is delivered by the line |22 to the advance line |04 and is exhausted from the return line |06 to the discharge line |24. In the return position of the stem II4 to which the latter is shifted by energization of a solenoid |34, pressure fluid is delivered by the line |24 to the return line |06 and is exhausted from the advance line |04 to the exhaustor dishargejline |24.

The hydraulic motor 2 is operated by an hydraulic system comprising a pump |38 having its :suction side connected by a line |46 to the hydrauvlicrluidin the tank |26. The discharge side of the pump |38 is connected by a pressure line |42 tchathe. casing-|44 of an operating valve, di- 1Aagrammaticall-yillustrated at |46. The casing |44 is-connected Vto an exhaust or discharge line ;-|48 eonnectedrtojhe tank |26, and the casing |44 is also connected to an advance line |50 communicating with the advance chamber I0 and is connected to a return line |52 connected to thereturnzchamber |2.-

The vali/e446 comprises a. rotor |54 within the casing |44., Saidrotor having a pair of peripheral -notche s, or .recesses |56 and |58 and having a ltransverse-bore orport connected to one end of thegrecessf. g The 'rotor |54 is operated by la lever-|62 illustrated inFigurel in its neutral position, whereat pressure fluid .is delivered by the pressure-line |42 to the exhaust line |48. As the leven|62 isnrotated clockwise as shown in they drawing, the rotor |54 is shifted to ad- Yf,Vancerpositionwhereat exhaust line |40 isy open to communication; with the line |52 by the notch I58, andthe pressure line |42 is open to communir-:ationwith` the advance line |59 by the notchv |56. Rotation of the lever |62 counterclockwiiSe-from itsneutralposition shown in the gdrawing-actuates,the rotor |54 to the return or pullback.position-thereof whereat the pressure f1; line |42 isfregisteredwith the port |60 and thus @,communicatesfthrough the notch |56 with the returndine |52, atthe same time that the ad- Y-vance.- line |50 isz-.open to communication with the exhaust line v|48 by means of the notch |56.

The lever |62 is operated, as hereinafter described:in.detai1,: by :an voperating rod |64 carrying spaced..collars Y|66 and |68. The rod is slidably iittedin -a complementary opening through an operating arm |10 carried by the spring plate 20. The flower. end of the rod |64 is pivoted at |12 to a'control. lever |14 pivoted at |16 to the machineyframewand having a foot pedal |18 f adapted for actuation by the operators foot to initiate the cycle of the machine; as hereinafter discussed-,in connection. with the operation thereof. .The end of the lever |14 remote from the pedalcH is provided with .an abutment or .bearing surface |60 :adapted for engagement by y@02a rod |82 of fa piston v|64 reciprocal in a pneu- \maticvcylinder-|86 and defining advance and return chambers |88 and |90 therein. The advancechamber |88 is connected to an advance line |92 and [the return chamber nected toa return line |94, said lines being con- .nectedl to-lavconventional operating valve |96 .-which'- is similar to valves 68 and |68 and is connected/tothe pneumatic supply line 14. The valve-|96 isA normally urged by a spring |91 to `:reverse position, whereat the line 14 is connected to the return line |94. and the advance line |92 is exhausted by an-exhaust line |99; and the valve y|96 is. actuated to advance position, as hereinafter. discussed, by `a solenoid |98.

It will be understood that as the cylinder 58 is is cony rom, the centering chuck 44 is maintained Y in Predetermiesi alignment with `chuck it by.` means of a guide bracket 206 removably secured aS by screws 202'fto thetab1e 66. The ,bracket 200.' .2.5 .besfseen in Figure 2, is afforded an accurate machined nt as at 264 with complementary guide surfaces formed on the cylinder 58. Thus movement of the cylinder 58 is accurately guided l at all times to maintainthe chucks 44 and I4 in predetermined alignment.

Referring now to Figure 3, the lower end of the r,ram 6` and the chuck mechanism I 4 are g shownrin detail and it will be seen that the latch mechanism 30 comprises a cam member 206 having'a slidable lit within a complementary chamber 208 of the head I6. In the advance position of ythe collar 32, shown in Figure 3, the

mechanism30 `is maintained in operative posi- 1 .tion b y engagement of the member 206 with an abutment surface 2I0 within the collar thereby compressing a spring 2| 2 housed within the chamber 208 and reacting between the head I6 andthe cam member 206. A latch member 214 is housed within the cam member 206 and is slidably `interlocked therewith by a slot 2I6 in the latch member 2I4 and a `pin 2I8 carried by the vcam member 206. A spring 226 is also housed within the cam member 266 and reacts between the members 2|4 and 266 for urging,r

them apart to expanded position, as shown in the drawings.

Thus it will be seen that the latch mechanism 30 comprises a resilient latch unit 206, 2I4 andl 226 which extends into the socket 22 to engage the broach 26 within head I6. The latch unit is resiliently urged to inoperative position by the spring` 2I2 which is compressed by the collar 32 in the operative position of the mechanism 30, as seen in Figure 3. It will be understood that as the collar 32 engages the work, the head I6 moves downwardly with respect to the collar 32 thereby compressing the spring 34 and permitting `the member 266 to enter a. recess 222 in the inner perimeter of the collar` 32, whereby the spring 2I2 urges' the latch mechanism 30 from the socket 22 to inoperative position thereby releasing the broach 26. On the return or pullback stroke of the ram 6, the spring 34 returns the collar 32 to the advance position shown in I Figure 3 forcing a cam surface 224 of the cam member 206 inwardly along a complementary cam surface 226 of the collar 32 at the upperv end of the recess 222. In the operative position of the latch mechanism 30, as shown in Figure 3, the member 2 I4 is resiliently urged into i the socket 22 by the spring 220 and presents a cam surface 228 engageable with a complementary conical cam surface 230 at the upper end of the nose 24, as the broach 26 is urged to engaged position with the chuck I4, as hereinafter described in connection with the operation of the machine. It will be understood that after mechanism I4 with respect to the ram 6.

rial,'.such'j as tool steel-1' adapted to bear against theupper endgof the broach lnose 24. The head I6 is also providedwithfa longitudinal passage 236 communicating with the recess232 to aord al convenient conduit for a knock-out tool (not shown) utilized in the removal of the plug 234. The .head I6 is `preferably secured tothe Sprint,r plate 20'as by one or more screws 23B to maintain the head and plate inrassembled relationship during application and removal of the chuck The lower end of the head is provided with an annular pad 240 of hard material, such as tool steel, adapted to engage the bushing 38 as the latter is pressed into the hole of the work piece, as is hereinafter describedin connection with the 0D- eration of the machine.

As best seen-in Figure 3, the work piece may comprise a boss 242 around the hole 244 therethrough, and to insure release of the broach by the latch mechanism 36, thelower end of the collar 32 is preferably provided with one or more removable lugs 246 secured thereto, as by a screw 248, and projecting into the collar 32 beneath the head I6. The lug 246 is adapted to engage the boss 242 on the advance stroke of the ram 6, and it will be noted that the radially inner surface of the lug 246 is registered with a complementary recess 250 within the head I6 affording clearance for the lug 246 as the collar is urged to release position, while the pad 240 presses the bushing 38 into the hole 244:

Describing the operation of the machine and the electrical actuating circuits associated with the above-described hydraulic circuits, as shown in Figure 1, the cycle of the machine is initiated by actuation of the pedal |18 to the positionA shownwin phantom 'lines thereby rotating the rotor I54 of valve I 46 clockwise to the advance .delivered to the advance chamber I0 and is exhausted from the return chamber I2 urging` the ram 6 on the advance stroke thereof toward the work piece 52. Under these conditions the centering chuck 44 is in its advance position received within the opening 244 of the work piece, and the valve Hi8 is in its return position due to closing of a switch 218 by a ram arm 254, as hereinafter discussed in connection with the return stroke of the ram. As the ram moves on its advance stroke, the nose of the broach 26 4 tank |26.

the broach 26 has been urged to its extreme upward position within the socket 22, the latch 2 I4 is snapped into the broach Vrecess 28 by the spring 220 aording a positive lock for the broach until the latch mechanism 36 is released by the spring 2I2 as the collar 32 is actuated to release position whereat the member 206 enters the recess 222, as above described. v

The detailed construction of thehead l`6 is spring plate 20 `contacts a switch 256 closing a thereof connected to a `lead 260, the other ter-` shown in Figure 3 wherein it will be seen that' i the upper end of the socket 22`is provided 'with a recess`232 having a plug"234 of hard maten After thefl'arge end of the broach 26 has passed `through the opening 244, the bushing 38 is pressed into place by the head I6. Thereafter, thel arm I'I contacts the collar I68 to actuate the valve rotor I54 of the valve l46 to neutral position as the ram arm 254 carried by the circuit through solenoid I'36 which may be traced from a voltage supply 258 having one terminal minal of said voltage supply being connected to ground as at 262. rEhe lead 268 is connected to one terminal of the switch 256, the opposite ter- "minalof which 'is connected to a'lead 264 conposition of the valve whereat pressure fluid is' aclara-.1.41%faA nectedto-:one terminal. ofthe solenoid.-.|36, the

opposite 1terminal-of|which:-is connected-to a.

thereotlagainst the resistance of work 52 with the collar 32 `in y--release `position thereby releasing the latch ymechanism .38 of the chuck I4, the piston 92 -operating `the lever. 18 retracts the cylinder 58 of the broach retriever mechanism downwardly until the broach .26- is in the position illustrated in Figure 3 vbelow the level of the work,.52.

At this point, a conventional time delay device 210 -in abranch lead 212 of'lead 264 closes a circuit through the solenoid.y |98, one terminal of which is connected/to a lead 214 connected tor the time delay device 210, the opposite terminal of solenoid |98 being. connected to ground as stroke-within the guide bracket 269. As the cylini der 58. andi-chuck 44 move upwardly, the operator may place-anew bushing 38 on the breach preparatory toinitiation of a new cycle.

As the cylinder 58 moves upwardly on its ad- Vance stroke toward the motor 2, an arm or lug 282 on the cylinder engages an actuating spring 284 of a -normally open snap action precision ,switch 286 momentarily closing the latter thereby establishing an electrical circuit which may be traced from the voltage supply 258 to the lead 268 and a branch lead 288 thereof which is connected to one terminal of the switch 286, the

of the solenoid'10, the opposite terminal of which at 21,6. Energization of solenoid |98 shifts valve a counterclockwise directionunder the action`V of piston |84 until the rotor |54 ofvalve |46 has l-reachedthe return or pullbackposition thereof whereat pressure fluid is deliveredto the pullback chamber-I2 and is exhausted from the advance chamber Ill, whereupon the ram 6 moves upwardly on its return-orv pullback stroke. As

the ram -6 moves on itspullbacky stroke, withv the broachA retracted from engagement with the chuck I4, as abovedescribed, the spring 34 advancesthe collar 32 to appliedposition thereby u actuating ythe latch mechanism 30 of the chuck I4 tof operative position, as above described. When the collar 32 has beenretracted from the work piece, -said-workpiece may be removed by the operator.

As the ram 6 moves upwardly, the switch 256 is opened breaking the circuits through solenoidsY As the circuitthrough solenoid v |36 and |98. |98 is broken, the valve |96 is automatically shifted ,by spring |91 to return position, whereat pressure iluidi'is deliveredby -the line 14 to the return line |94 and isexhausted from the advanceline |92 through the exhaust line |99.

When the ram 6 reaches the top of its stroke, the arm |10 engages the collar |66 shifting the rotor |54 of` valve |46 to rneutral position, and the arm 254 closes a switch 218 establishing a circuit from the voltage supplyi258 through the switch, 218 and a lead 286 which is connected to one terminal of the solenoid |34, the opposite terminal of which is connected to the beforementioned lead 266 which is connected at 268 to ground.y Energization'of solenoid |34 actuates the valve.- I08 toreturnposition whereat pressure fluid isdeliveredby the pressure line |22 to the return-line |86 and is-exhausted from the advance line |84 to the exhaustline |24, whereupon the piston-:9,2` -isurged lupwardly on .its return'strokev moving. the cylinder upwardly Vonv advance V111881,15 OmpI'iSinga.-pressurehead with a socket is connected to a lead 296 which is connected to ground as at 216." lllnergization of solenoid 294 shifts the valve 68 tovadvance position whereatv pressure ud is delivered to the line 64 and is exhausted from the line 66 by the associated exhaust line 15 connected to the valve. Thus the Y piston 56 is advanced-rapidly within the pneumatic cylinder 58 advancing the piston 56 toward the chuck 4I4 as the cylinder 58 is advanced v toward the chuck by the lever 18 and its operating piston 92.` With the piston 56 at the top of tits stroke relative to the cylinder 58, the nos-e 24 of the broach is spaced below the latch mechanism 30, a ldistance approximately equivalent to the distance between switch 286 and a switch 300 operated by a spring. 382. Thus with the piston 58 atthe top ofiits stroke, the cylinder 58 is advancedy upwardly by the lever 18 to engage the broach nose 24 with the latch mechanism 3.0, whereupon the lug 282 engages the vspring 302 momentarily actuating the normally .open switch-300 closing afcircuit through the 4:solenoid 12 which may be traced from the voltage :supply 258 tothe lead 260 and the branch lead 288 whichis connected to one terminal of the .switch 300, the opposite-.terminal or which is connected to a lead 394 whichis connected to Kone terminal ,of the solenoid 12, the opposite ter- :minal of `which is connected to the lead 296 which, as above noted, isgconnected at 216 to ground. Thus actuation ofy switch 398 energizes solenoid 12 which actuates the valve 63 to return position thereof Whereat pneumatic pressure uid from the line14 is directed to the return line 66 and pressure Huid inthe advance line 64 is exhausted Ithrough the associated exhaust line 15, thereby retracting piston 56 and chuck 44 to Vthe position shown in Figure l preparatory to in- -sertion of another work piece and initiation of a new cycle by the operator;

In the event that the operator desires to ter- Ininate-operationlofv the machine-at the end of any cycle thereof,the switch 292 may be opened thereby. preventing the :closing of a circuit through solenoid 1|) upon actuation of the switch -Thus at the top of the advance stroke of the cylinder 58, the broach nose is spaced below the chuck I4, whereuponrthe operator may remove the broach for the purpose of terminating operationfofthe machine or to substitute a new breach, if desired.`

We claim:

,1. A machine of the class described, comprising a fluid motor includingvcylinder means and ram means presenting spacedv advance and return areastherein, a-chuck carried by said ram adaptedfto receive .one end of an'associated tool,

' 4a'collar on said head, spring means for urging said collar to an advance position on said head,

` tool engaging means carried by said head and communicating with said socket, said collar being operatively connected to said engaging means for holding the same in operative position 'c when said collar is in advance position and for releasing said engaging means when said-collar is in retracted position relative to said head, a ltable adapted to support an associated work piece and having a tool receiving opening, a fluid pressure device beneath said opening comprising a cylinder member and a piston member therein',vv tool advance position thereof Whereatfpressurefluid is delivered to said advance area and` isexhausted from said return area, means for yaut omatically shifting said valve means to neutral position when said ram means reaches advance position relative to said table, means for automatically actuating said second uid motor to retract said device when said ram reaches advance position, means for automatically shifting said valve means to return position at a predetermined time inmotor, means for automatically actuating said second motor to advance said device when said ram reaches return position, and means for automatically actuating said device first to advance 4and then to retracted position thereof as said second motor actuates said device on the advance stroke thereof. c f

2. A machine of the class described, comprising a iiuid motor including cylinder `-means and ram means presenting spaced advance and return areas therein, a chuck carried by said ram means comprising releasable latch means adapted tointerlock an associated tool withfsaid chuck, atable adapted to Support an associated Work terval subsequent to actuationof said second4 for automatically actuating. said second ,fluid motor to advance-said .device when said ram means reaches return position, and means for automatically actuating saiddeviceto advance position thereof as said device is advanced by said second motor to re-engage an associated tool with said latch means, and means for thereafter automatically .actuating said device to retracted position thereof.

3.A breaching machine comprising a Work support, a broach operating chuck having releasable means for engaging an associated broach, powermeans for advancing said chuckl toward saidwsupport and for retracting said chuck from 'said support, acentering chuck opposedto said `operating chuck, said centering chuck being adapted in advance position to` engage and center .an associated broach actuated by said operating chuck and being adapted to retract under the thrust of said broach, and operating means .in-

vdependent'of the First-mentioned means for re- 'jturn'in'g said centering chuck to advance posi- 'tion upon retraction of said operating chuck,

said operating means comprising a pair of fluid pressure motors arranged in series, said motors being formed and arranged, upon actuation of both, to engagey said broach with said operating l chuck.

4. A broaching machine comprisinga breach ,operating chuck, a breach having breaching means extending lengthwise from a point 'ad- ,vjacent one end thereof to a point adjacent the vopposite end thereof, releasable latch means carried by'the chuck for interlockingl said opposite end of said broach therewith, means for adfvancing and retracting said chuck, a work supadapted to support an associated Work piece, [a centering chuck, `means for advancing and re- `tracting the centering chuck with respect to theoperating chuck, said centering chuck being adapted in advanced position thereof to engage the iirst mentioned end of said broach and to `'thereby maintain thevbroach in predetermined l alignment with respect to said Work piece, and

meansv carried by the operating chuck and engageableon advance `stroke thereofv directlywith the work piece for automatically releasing said c latch means. 1`

piece and having a tool receiving opening, a iiuidg-fl pressure device beneath said opening,` tool engaging means operatively connected to said device and adapted in the advance position of said device to project through said hole, a second fluid motor operatively connected to said device, and automatic control means comprising valve means for alternately delivering pressure fluid to and exhausting pressure uid from respective areas, means for shifting said valve means to advance position thereof whereat pressure fluid is delivered to said advance area and is exhausted from said return area, means for automatically shifting said valve means to neutral position when said ram means reaches advance position relative to said table, means for releasing said latch means in said advance position of said ram means, means for automatically actuating said second fluid motor to retract said device When said ram means reaches said advance position thereof, means for automatically shifting said valve means to return position thereby directing pressure fluid to said return area and exhausting pressure iuid from said advance area at a predetermined time interval subsequent to actuation of said second motor, means 5,l A machinel of the class described, comprising a tool operating chuck, motor means operatively connected thereto for advancing and retracting the same, releasable tool engaging means carried by said chuck, another chuck opposed to the first-mentioned chuck, a pneumatic pressure device operatively connected to said other chuck for advancing and retracting the latter relative to the rst-mentioned chuck, hydraulic motor means independent of the iirstmentioned motor means and operatively connected to said device for advancing and retracting the latter as a unit relative to the iirst-mentioned chuck, and means carried by the firstmentioned chuck and engageable with an associated Work piece in the advance position of the first-mentioned chuck to release said tool engaging means.

6. A machine of the class described, comprising a iiuid motor including cylinder means and ram means presenting spaced advance and return areas therein, a chuck carried by said ram means and comprising releasable latch means for engaging an associated tool with said chuck, an opposed centering chuck spaced from the tool in retracted position of said ram means, a iiuid pressure device having cylinder and piston members,

one of said members being operatively connected and retracting the same asa unit with respect to '-'s'ai'dfram means.

-7.'A `broaching machine comprisingra b roach operating chuck, a broach 'having *broaching means extending lengthwise thereof from one end "thereof and having bushing support means ait the --"'-op`posite endthereof; releasable latch means car- 'I ri'e'dv by the chuck for interlocking said -opposite end fof'4 said `broach therewith, motormeans for advancing and retracting said chuck,a work supporta'dapted to support lan associ'ated'work piece, 'a' centering` chuck, means for advancing and re- ,'tr'actifng the centering chuck with'respe'ct to the operating chuck,"y said centering chuck 'being AVI@adapted in advanced position thereof vto engage andmaintain the Ybroach in predetermined align- -m'ent With-respect `to said work piece; and 'means `carried -b'y` the operating 'chuck andenga'gleable von thefadvance stroke thereof Vwith the Work piece Vfor 'automatically' releasing Asaid latch `r`means.

58.A`br`oaching -machine comprising a' `frame and-a hydraulic'motor Vincluding cylinder means and ram means defining advance and'return otherof said members, saidievicevr being operativelypon'nected t the centering A'chuck for actuation thereof. i

91 `vA machine of the classdescribed; comprising 'a chuck adapted to operate lan' associated'tool,

y hydraulic motor means connected'to' saidichuck for advancingand-retractingy the same, fa* cen- `vtering' chuckopposed to thek rstmentioned lchuck;` 'a' pneumatic fluid pressure device operatively connected to said centering chuck for' advancing and retracting the' latterrelative to the first-,mentioned` chuck, and hydraulic motor means' independent of the first" motor means and operatively connected `to said device fr advancing and yr'etracting the latter as a unit with respect to the rstmentioned chuck.

ljAbfroaching machine comprising' a" frame and a hydraulic'A 'motor including cyiinder'nieans "ad rarn meansV defining advance and 'return chambers, one of Vsaidfmean's; being anchored to the" frame, a -brjoach Vopierating chuck operatively connected to the 'other of said means, releasable 'latch means carried lby said chuck foriengaging an associated breach, af'rn'iprocal centering chuck opposedto' `the operating chuck, a kfluid pressure device comprising piston' and' cylinder ie'lements, one of :which is operatively connected `to the centering `cl'lnfnzlLuand motor means comprising cylinder and piston members, oney 'ofJ said members bein'g'anchored to theframe'tan'd the other of' said'nembersbeing operatively con- `1ectedtothe other elementjof said device for reciprocating the' latter andthereby reciprocating the centering chuck.

11i-,A loroachi'ng `machine comprising'f'a''work supportfoppos'edi"chucks] meansl for positively i guiding said"cl"iucl;s in predetermined alignment f withrespetto said support, an'dmea'n's for advancing andreturning'each'chuck xvithiresp'ect to the other, the means associatedv with cnefchuck being independent of the means- 'associated' With the'other chuck and comprising a pair'offluid motors'arranged 'in series, the other chuck comprsing releasablel vbroach-'engaging means, and

means' for releasi-ng-saidengaging 'means'in ad- Vance position Of Sdimer Chuck ARTHUR A v-vvEtsBERGER.

ROBERT-Ji HELTON.

*References Cited-n the le'f this-patent 

